Update docs index (#17246)

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---------

Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

(cherry picked from commit c2d9ec4)

docs/source-pytorch/community/index.rst

@@ -0,0 +1,68 @@
+
+.. toctree::
+   :maxdepth: 1
+   :hidden:
+
+   ../generated/CODE_OF_CONDUCT.md
+   ../generated/CONTRIBUTING.md
+   ../generated/BECOMING_A_CORE_CONTRIBUTOR.md
+   governance
+   ../versioning
+   ../past_versions
+   ../generated/CHANGELOG.md
+
+#########
+Community
+#########
+
+.. raw:: html
+
+    <div class="display-card-container">
+        <div class="row">
+
+.. displayitem::
+   :header: Code of conduct
+   :description: Contributor Covenant Code of Conduct
+   :col_css: col-md-12
+   :button_link: ../generated/CODE_OF_CONDUCT.html
+   :height: 100
+
+.. displayitem::
+   :header: Contribution guide
+   :description: How to contribute to PyTorch Lightning
+   :col_css: col-md-12
+   :button_link: ../generated/CONTRIBUTING.html
+   :height: 100
+
+.. displayitem::
+   :header: How to Become a core contributor
+   :description: Steps to be a core contributor
+   :col_css: col-md-12
+   :button_link: ../generated/BECOMING_A_CORE_CONTRIBUTOR.html
+   :height: 100
+
+.. displayitem::
+   :header: Lightning Governance
+   :description: The governance processes we follow
+   :col_css: col-md-12
+   :button_link: governance.html
+   :height: 100
+
+.. displayitem::
+   :header: Versioning
+   :description: PyTorch Lightning's versioning policy
+   :col_css: col-md-12
+   :button_link: ../versioning.html
+   :height: 100
+
+.. displayitem::
+   :header: Changelog
+   :description: All notable changes to PyTorch Lightning
+   :col_css: col-md-12
+   :button_link: ../generated/CHANGELOG.html
+   :height: 100
+
+.. raw:: html
+
+        </div>
+    </div>